Flying Camera Satellite Images 1999

The following images are reproductions of aerial
photographs and satellite images,
held in the Lloyd Reeds Map Collection, McMaster University Library.
The original source of each image is indicated when known.
The collection is called "Flying Camera" because the majority
of images are from the annual Fliegende Kamera/Flying Camera
calendar, published in Stuttgart.
The images are available in the Map Collection in paper format
only, and may be borrowed by McMaster University students for
class presentations.

Those regions of the eastern Andes located some 150 km north of Mendoza,
Argentina, are characterized by north-south trending mountain ranges.
The contours of these ranges delineate the path of fault systems in the
Earth's crust, and the mountains themselves were shaped during the process
of Andean orogeny and ensuing east-west crustal compression.

This region comprises areas with widely varying elevations, ranging
from the snow-covered and glaciated peaks of the Andes (blue, lower left)
with South America's highest mountain, Mount Aconcagua (6960 m), to the
low-lying plains of the Argentinean Pampa, with elevations of less than
1000 m (lower right).

The San Juan River cuts a zigzag path through the rugged morphology
of the region. Green slopes and escarpments are visible along the banks
of the upper tributaries of the river (left). Here grasses and shrubs
have gained a toehold in the relatively fertile volcanic gravel. A broad
dark-colored zone of 3000- to 4000-m-high mountains, still covered with
snow in this spring image (blue), can be seen further to the east. These
mountains are made up of older (pre-Mesozoic) layered and partially deformed
sedimentary rocks. Similar rock formations also comprise the oval-shaped
Sierra Pié de Palo (upper right).

After cutting deep gorges into the heavily folded older rocks of the
sub-Andean foreland (wide dark north-south band) on its path eastward,
the San Juan River flows into a broad, shallow delta-shaped valley. Although
the valley is arid, numerous irrigation channels have made the development
of agricultural plots possible here. The fields form green-patterned areas
clustered around the city of San Juan. Light gray patches represent dried-out
lakes along the river's course as it drains to the southeast. The dryness
of the climate in the region is underscored by structures which resemble
sand dunes (right center).

Schleswig-Holstein owes the characteristic appearance of its countryside
to Scandinavian glaciers which deposited layers of rock and soil, in some
places more than 100 m deep, during various glacial advances. Since the
glaciers approached from the east, the land that is now Schleswig-Holstein
can be divided into three distinct zones. In the eastern parts, hilly
regions, rich in lakes and fertile loamy soil (drift topography), were
left behind by receding glaciers at the end of the last ice age (Weichsel
Glacial Period). Along Schleswig-Holsteins "center line", a belt of Geest,
sandy and poor soils that support little vegetation other than heath,
and older moraine remnants stemming from the Saale Ice Age were left behind
on the glacial outwash plain. Along the west coast, however, polders have
been built on the North Sea and very fertile marsh lands grow upon Saale
Ice Age boulder clay deposits. The tops of older moraines occasionally
peek out of the marsh like islands in the sea ("Geest-kern"), for example
on the islands of Sylt and Föhr. Farmers liken Schleswig-Holstein's
countryside to "two slabs of ham on a lean bone".

The Eider peninsula, with its clayey silty soil, belongs to the fertile
marsh lands. Ooze from the North Sea makes for heavy and rich soils, which
can at times also be very dense and waterlogged. In order to deal with
the problems of heavy and wet soils, farmers began to dig pits during
the 19th century to reach the lime-rich layers of rubble in
the ground moraine underneath. This lime marl was then used to fertilize
and loosen the soil in their fields. These nearly circular "holes" are
still visible in practically every field in the region. The pits were
usually dug in the center of a field to make it easier for farmers to
reach the total surface area with their difficult- to-maneuver horse-drawn
wagons with a minimum of effort.

Today, in the age of chemical fertilizers, marlpits are no longer used.
They are overgrown by vegetation, and water frequently collects in their
depressions. In an effort to preserve or even to revive important ecosystems,
old-style agricultural "monuments", such as high-growing hedge-rows (Knicks)
which shelter fields from winds, are now protected by law. Preservationists
are striving to maintain the largest of the marlpits as small biotopes
within intensively cultivated farming areas for future generations.

Located on the southern branch of the Garonne River, Bordeaux is the
fifth largest city in France and the largest French city on the Atlantic
coast. Together with its suburbs (left center) it counts more than 700,000
inhabitants, making it the undisputed capital of the Aquitaine region.
Traditionally the city lies at the heart of the Garonne valley, near the
mouth of the river and close to the "Les Landes" plain to the west and
southwest of the city, as well as to the "L'Entre-Deux-Mers" hills to
the northeast. A port city since the 12th century, Bordeaux
owes much of its prosperity to a flourishing wine trade with England.
In the 18th century the city became a pivotal point in colonial
"triangular" trade, transferring goods and slaves between the West Indies,
Africa, and Europe. The harbor now lies at a distance of 100 km from the
ocean and it's struggling to deal with the problem of siltation in the
Garonne Estuary (upper center). Although its world renowned wine trade
is still a major source of prosperity, Bordeaux's industries are less
developed than those in other French cities. Bordeaux draws much of its
importance from its position as a regional and administrative center,
and from its regional media and universities.

The Bordelais region is renowned for vineyards which carpet the gravely
hills, the "graves", between the left bank of the Garonne and the Bay
of Biscay. Under English rule during the Middle Ages wine production was
aimed at producing table wines for the English market. It was not until
late 17th and early 18th centuries that fine quality
wines began to be produced.

In this image only a small portion of the Landes Forest (dark green,
left center) is visible. With its 1 million hectares the Landes Forest
is the largest wooded area in Europe. Whereas it was a source of wooden
supports for use in mining shafts, resins and paper pulp in the past,
this region is now an important supplier of wooden building material,
etc. Astonishing for this region of the Médoc district are immense
irrigated farms which produce corn in monoculture (light green pockets).

The Médoc district is separated from the Atlantic Ocean by a
straight, sandy coastline (white line running north-south). This strip
extends far to the southwest as Cap Ferret at the mouth of the Basin of
Arcachon (black and gray, lower left), where oyster fishing is an important
industry. Following the development of spas along the protected coasts
of the Basin of Arcachon and Médoc lakes (lower left), tourism
now plays a decisive role in the rejuvenation of commerce in the Gascogne
region.

In 1293 Stralsund, which derives its name from its location on the Strela
Sound (Strelasund), became a member of the Hanseatic League, thus entering
into rivalry with other Hansa cities on the Baltic Sea, in particular
with Lübeck, with which it has much in common architecturally. The
feud between the two cities began very early when troops from Lübeck
set fire to Stralsund, which was built entirely of wood at that time,
in 1249. But Stralsund quickly recovered from the attack. Its citizens
rebuilt the city with bricks, became clever and adroit merchants, and
helped Stralsund to gain a strong position of power. In the "Peace of
Stralsund" treaty drawn up with Denmark in 1370 the Hanseatic League strengthened
its position of hegemony within northern Europe and Scandinavia. Even
Wallenstein and his troops remained unsuccessful in their siege of the
city and, thanks to the assistance given by Swedish troops, were forced
to withdraw empty-handed. This support had, of course, its price, and
Stralsund was ruled by Sweden for nearly 200 years until it fell to Prussia
following heavy fighting with Napoleon's army in 1815.

The island which forms the heart of the old city of Stralsund is surronded
by the Knieperteich and the Frankenteich, two large ponds, as well as
by the Strela Sound. Numerous medieval, renaissance and baroque historic
buildings are within short walking distance of the island. Two of the
city's main attractions are the City Hall, begun in 1270 to resemble Lübeck's
Rathaus, and the Church of St. Nicolai, dating from 1276, with its Gothic
and baroque altars and the world's oldest astronomical clock, built in
1394 (top of center). The Johannis Monastery was built at approximately
the same time and draws visitors to its baroque library and splendid rose
gardens. Several 14th- to 18th-century townhouses
which surround the old market square are also worth seeing, among them
the so-called "Scheele House" in "Ferry Street" (Fährstraße),
painted in a bright red and dating from the year 1350. This house bears
the name of chemist Carl Wilhelm Scheele, who was born there in 1742 and
later emigrated to Gothenburg. Scheele is renowned for his discovery of
the element oxygen, and scheelite, a source of tungsten and its compounds,
is named after him. St. Katharine's Convent, now home to two museums,
lies somewhat further to the southwest, as does the church of St. Mary.
St. Mary's 104-m-high tower offers one of the most splendid views of the
city of Stralsund and the island of Rügen.

Stralsund is connected to Rügen by the "Rügendamm", a rail
and road embankment which was built in 1935. The harbor, once Stralsund's
lifeline, now seems barren and sober with its cranes and shipyards. The
waterfront comes to life only when ferries from Rügen and the smaller
neighboring island of Hiddensee dock, and crowds of visitors flock from
the promenade bordering the waterfront to the old city ramparts, which
are now topped by roads and highways. But, in spite of the ravages of
modern municipal development, many towers, battlement walks and watch
towers which played an important role in the defense of the city are well
preserved. On the outside of the old fortifications, between the ramparts
and the Baltic, a sprawling green belt has grown up.

This Landsat image of the northwestern part of the Somalia is now satellite
remote sensing history. Dating as it does from the second year of operation
of the system, then called ERTS 1, it is evident that the system was limited
in its ability to reproduce details. Red colors, however, clearly denote
the transition from low-lying coastal semi-arid areas along the Gulf of
Aden to dry savanna regions rising to the south. Dense, fresh vegetation
is visible as bright red patches on mountain peaks at elevations of around
1600 m (right). These patches delineate topographic lines in highly dissected
uplands underlain by sandy to clayey lower Cretaceous rocks to the southwest,
and again appear as red patches in kilometer wide, branching valley floors,
which drain to the southeast on the other side of a low water divide.

Even large cities, such as Berbera (right) with its more than 50,000
inhabitants and Hargeysa (lower center), the capital of the region with
more than 100,000 inhabitants, are barely discernible. In addition to
these cities, three other small coastal towns as well as very sparsely
populated pastoral nomad territories, Guban in the north and Habrawa in
the south, can also be seen.

Drainage systems are generally directed toward the north, forming a
plain of alluvial fans up to 50 km wide south of the coastal barriers
and terraces along the Gulf of Aden. Varying colors and closely spaced
dissection patterns bear witness to the countless generations which have
formed these barriers and terraces. Periodic water run-off toward the
coast, as takes place today, follows a well-defined river bed (whitish
in color) with numerous embankment and sand terrace systems. From time
to time, this drainage pattern is lost beneath a fluvio-aeolian sand plain
(whitish color, right). Bluish strips at its edge trace the paths of the
northern monsoon.

This system of alluvial fans surrounds plateaus (black) which are composed
of the heavily dissected erosion remnants of Tertiary basalts. Basaltic
remnants are also visible in hilly areas to the south. These remnants
are the eastern extensions of a volcanic system accompanying the opening
of the East African Rift Zone and the Gulf of Aden. Within the transition
from the coastal plain to the hilly country beyond, a mountain range,
heavily folded parallel to the coast and dating from the Precambrian to
the lower Cretaceous, is visible.

Old folded Precambrian rocks are found further to the southwest. This
finely dissected area, stretching to the main water divide, is underlain
by the soft lower Cretaceous beds described above. On the other side of
the divide undissected areas interweave with younger dissections. The
texture of these features, which break off sharply at the edges of the
plateau, is characterized by the dry savanna vegetation arranged in parallel
stripes. In West Africa this type of vegetation is known as "brousse tigrée"
(tiger-stripe bushland).

Berthold IV, duke of Zähringen, founded the city of Fribourg in
1157 on a meander loop in La Sarine (Saane) River, which winds its way
from lower left to upper right through the aerial photograph. The river
cuts a path through 100 m of molasse plateau, shaping several terraces
in the process. The old city (center right) is located on a 100-m-wide
loop (center terrace) 40 m above the lower river bank (the Bourg); the
Neuville, Auge and Planche (Matte) quarters form the lower part of the
old city on the river flood plain. The city has grown on to the upper
terrace (train station) and the surrounding molasse hills since the 14th
century.

Parts of Fribourg's old city have been laid out in a geometric pattern.
Three rows of houses run parallel in the Bourg and near the train station.
Three rows of houses run parallel in the Bourg and near the train station.
The Gambach quarter, also in the vicinity of the station, was built in
a checkerboard pattern, and the Boulevard de Pérolles, leading
south from the train station, forms a broad axis in the schematic design
of the Pérolles quarter. The Pérolles quarter was built
after the construction of the Pérolles dam (1870-73) and the ensuing
first stages of industrialization in the city. Cables delivered hydraulic
power to several factories located on the Plateau de Pérolles.
Today the School of Engineering and the Faculty of Mathematics and Natural
Sciences are housed in the old industrial areas; further university building
construction is planned. Of the city's former industrial base, only a
coffee and chocolate factory and a brewery survive.

The regions between the Aare and Saane Rivers have been transitional
zones between German and French cultures, between Alemanni and Burgundians,
since the 5th century. This is most likely the reason that
the city and canton of Fribourg have always been bilingual. Today approximately
70% of the city's 29,000 inhabitants speak French; slightly less than
30% speak German, and the remaining inhabitants speak numerous other languages.
The city's multilingualism gives Fribourg a cosmopolitan flair, and its
university is the only bilingual university in Europe.

The aerial photograph shows not only the city but also an agglomeration
of villages and suburbs loosely grouped around its center: Marly to the
south, Villars-sur-Glâne and Givisiez to the west, and Granges-Paccot
to the north. These municipalities have absorbed the expanding population
of the city and have become popular suburbs. Furthermore, they offer space
for industries to settle (top) within close proximity of the highway from
Bern to Geneva.

For weeks on end millions of people in China fought a desperate battle
to stave off floodwaters of the Yangtze River which had plagued the country
since early July 1998. The devastation caused by this flooding is generally
viewed to be the consequence of human activities such as the clearing
of forests, construction of dams and the destruction of natural water
reservoir areas.

Information concerning the extent of flooding in China was gathered
by visibility independent radar sensors mounted on the European ERS-2
earth observation satellite and transmitted to a mobile satellite ground
station operated by the German Remote Sensing Data Center (DFD), an institute
of the German Aerospace Center (DLR), in Ulaanbaatar, Mongolia. This data
was then georeferenced and enhanced at the German Remote Sensing Data
Center to create a highly accurate composite image of the area with a
resolution of 25 m (accuracy approx. 70 m).

The satellite image portrays an area approximately 100 km x 100 km in
size located southwest of the industrial city of Wuhan. It is the composite
result of the mulitemporal overlayering of satellite data, that is to
say, images gathered at various points in time were combined to highlight
rising water levels. An image taken on August 1, 1998, shows flood levels.
Normal water levels, before flooding, are taken from ERS-1 data gathered
on June 9, 1993, by the Japanese Hatoyama satellite station, and were
subsequently processed by the European Space Agency (ESA), stored, and
georeferenced by the DFD.

Information from the June 9, 1993, image is shown in green, red hues
represent floodwater levels on August 1, 1998. In order to emphasize the
extent of flooding, the difference between water levels on these dates
is shown in blue. Areas which were covered with water on both dates, such
as rivers, lakes, or cultivated areas are dark blue, particularly in the
western portion of the image. In the eastern regions of the image, water-covered
areas are reddish due to radar reflection on choppy water surfaces during
windy conditions. The flood regions of Dongting Hu, a natural flood basin
lake on the eastern edge of the image, and the eastern course of the Yangtze
River to the north are not represented in blue shades. This is due to
the fact that agricultural areas in the reference image, seen in gray,
show values and structures similar to those caused by surface-water wind
rippling in the August 1, 1998, image.

The Costa Blanca has been invaded and inhabited by many different peoples
in the course of its history. The original inhabitants, the Iberians,
were displaced by Phoenicians in the 8th century B.C., who
founded trading settlements. They were, in turn, followed by Greek merchants
in the 7th century B.C., who brought the olive tree and grapevine
to Iberia. Beginning in the middle of the 6th century Carthaginians
founded large colonies along the coast. In the early 3rd century
B.C. the Romans conquered the Spanish Mediterranean coast, where they
stayed for the next 600 years. After the fall of the Roman Empire in the
5th century A.D. the coast fell under Byzantine influence,
and Visigoths gained control in the 7th century A.D. In the
early 8th century A.D. the region was incorporated into "al-Andalus",
the Muslim-controlled portion of the Iberian Peninsula. In the 13th
century, the Christian era began under the rule of the royal houses of
Castile and Aragon, which were unified through the marriage of Ferdinand
II and Isabella I (the "Catholic Kings") in 1474. Ferdinand and Isabella
were able to drive the Muslims from Spain. This is commemorated during
the festival of "Los Moros y Cristianos" which is celebrated with colorful
parades in many cities of the province.

Crowds of tourists began to flock to the Costa Blanca about 30 years
ago, attracted by the long white sandy beaches stretching along the Mediterranean
coast of the province of Alicante. The quiet fishing village of Benidorm
quickly became an important tourist resort. The old city with its narrow
streets huddles atop a rock tongue, the "Balcon del Mediterranea", dividing
two 5-km-long stretches of beach. This rock formation served as the foundation
of a fortification which was destroyed by the Spanish and British in 1812
during the Spanish War of Liberation against the French. The fortification
ruins afford a splendid view of the rocky wedge-shaped "Isla de Benidorm".
The island is uninhabited and serves as a kind of bird preservation area.
However, small boats regularly ferry tourists to the island. The northern
stretch of beach, the "Playa de Levante", is surrounded by high-rise hotels
and apartment complexes as well as by tourist attractions, amusement parks
and fairgrounds. Nightclubs, shows and discotheques offer a wide spectrum
of nightly entertainment. The "Playa de Poniente" south of the city offers
more calm and quiet. Beyond "Montbenidorm", a rocky ledge, the village
of La Cala and the "Playa de Cala" beach continue along the coast.

A highway has been built at the foot of the Sierra Helada coastal mountains
parallel to the coastline and the national road to offer tourists easy
access to the region. The highway exit leading to the national road is
visible in the aerial photograph. An "Aqualandia" amusement park has been
built nearby. Its various pools provide swimming fun for young and old
alike.

This satellite image mosaic was created at the German Remote Sensing
Data Center, an institute of the German Aerospace Center (DLR), in Oberpfaffenhofen.
Twelvve NOAA-11 AVHRR LAC (Local Area Coverage) data sets dating from
1989 to 1991 were combined to create this composite image. A digital land
model and cloudless satellite images were required in order to calculate
a realistic three-dimensional computer animation of the region. Patches
of cloud cover can, however, still be seen on the island of Sri Lanka
and the southern tip of the subcontinent; this is due to the limited number
of images available for these areas. Varying observation conditions during
the changing seasons can also lead to "sharp edges" on the image (for
example, lower center, Sri Lanka).

The Indian subcontinent was thrust up against the Eurasian Plate during
the process of alpidic orogenesis which began in the Paleogene and still
continues today. The collision of the two continental crust plates formed
the Himalayas. The border between the Indian and Eurasian plates runs
directly south of the snow-capped mountain ranges seen in the image. To
the north rises the Tibetan Plateau. Tibet's average elevation is approximately
5000 m. These unusually high altitudes are the result of very thick crust
(approx.. 70 km) in the region. The Tibetan Plateau, with its large lakes,
such as Tengri-nor (Namu Hu), is bordered by the peaks of the Kunlun Mountains
to the north and by the Karakorum Range to the west (upper left). To the
north of these mountain ranges the Takla Makan Desert is visible.

Northern India is dominated by the expansive plains of the Ganges-Brahmaputra
lowlands (light green). West of Dhaka (Bangladesh) the Ganges River and
the Brahmaputra River, which streams west and south from the Tibetan Plateau,
join forces before emptying into the Gulf of Bengal. The estuarine delta,
as is also the case with the deltas of the Naramada River on the Indian
west coast and of the Irrawaddy and Salween Rivers in southern Burma,
is characterized by brightly colored waters. Large amounts of suspended
particles are carried by the rivers from the eroding Himalayas or from
weathering tropical soils to the sea and deposited there. Bright green
colors to the east towards Bangladesh, Burma and Thailand, represent thick
vegetation predominant there.

The city of Amersfoort is located in the central Netherlands and is
named after a ford on the Eem (formerly Amer) River, which formed part
of an old trade route leading from Deventer and Kampen to Utrecht. First
reference was made of the settlement in 1028, and the city was granted
its charter in 1259. By the Middle Ages Amersfoort had become a flourishing
center of trade and industry, and was a member of the Hanseatic League.

City expansion had increased so far by the 14th century that
Amersfoort bulged beyond the confines of its city walls. A second fortification
wall was built between 1380 and 1450, with the result that Amersfoort
became the only Dutch city with a double wall system. The outer wall was
torn down in 1829; parks and a ring road surrounding the city were built
in its place (top).

The aerial photograph shows the nearly complete circle of the old city
center, dominated by the 100-m-high Tower of Our Lady, an imposing Gothic
structure dating from the year 1471 (right center). At one time the Tower
functioned as the bell tower of a church which was destroyed by an explosion
in 1787. The foundation ruins of the church can be seen in the open area
to the left of the Tower. Amersfoort's market square known as the "Hof",
is located in the center of the old city (lower center). In the Middle
Ages the lords of Amersfoort resided in a palace on the "Hof". The Romanesque
Church of Sint Joris, with its three naves, is located next to the market
square.

The only inner city wall gate which remains is the Kamperbinnenpoort,
dating from the 14th century (lower left). Only small remnants
of the old city walls are left. These remnants can be found inside the
so-called wall houses (muurhuizen), which were built on the inside of
the wall in a circle. When the second city wall was built in the 15th
century the original wall no longer served its function as a fortification,
and adjoining plots of land were sold by the city fathers. The new owners
built their houses on the inner side of the old wall and planted small
gardens on the outside of the wall, along the edge of the city moat. In
recent years most of these houses have been restored, resulting in the
creation of a picturesque city quarter with small courtyards, gardens,
and narrow bridges crossing the old moat - truly unique in all of the
Netherlands.

Lake Constance traces its origins to the last Ice Age, when its basin
was carved out by the ice masses of the Pleistocene Rhine glacier. The
lake then took on its current form when ice of the glacier melted approximately
10,000 years ago. Lake Constance has a surface area of 539 square km and
a maximum depth of 252 m. The lake's main body, the "Obersee" (476 square
km), which was known as "Lacus Brigantinus" by the Romans, is 45 km long,
stretching from Bregenz in the east to Konstanz (Constance) in the west.
Lake Constance and its environs have been inhabited from Neolithic times.
Stone and Bronze Age "pole construction" peoples were followed by Celts
and Romans and, after 260 A.D., by the Alemanni. Merovingian and Carolingian
settlements and monasteries were established there in the early Middle
Ages.

The "Swabian Sea"' has been referred to by German speakers as the "Bondensee"
(probably derived from the Carolingian imperial palatinate of Bodman)
only since the14th century, whereas it is referred to by the name given
by the Staufer dynasty "Lacus Constaniensis"/ "Lac de Constance" throughout
the rest of the world. Characteristic of the island and harbor city of
Lindau, located on the upper shore of Lake Constance opposite the point
where the Rhine enters the lake, are its patrician houses which bear witness
to bygone periods of prosperity and flourishing trade. Friedrichshafen,
which was founded in 1811 by the Württemberg King Frederick I, lies
further to the west. In the years following 1908 Friedrichshafen gained
a worldwide reputation as the city in which zeppelins were built. To the
west the lake is divided into two parts by the Bodanrück mountain
ridge. The northern basin, the "Überlinger See" (61 square km), is
flanked by the cities of Meersburg and Überlingen, a spa which is
auspiciously located along the old Ulm - Constance trade route. The island
of Mainau on the south shore is famous for its flowers. The southern basin,
the "Untersee" (63 square km), stretches from the old diocesan city of
Constance, with its historical old city, to the town of Stein am Rhein.
The island of Reichenau, home to numerous monasteries and a flourishing
vegetable production, has been connected to the mainland by a causeway
since 1838. The Gnadensee and the Zeller See are located to the north
and northwest.

The Rhine River, approaching from the south, flows into the Obersee
to the west of Bregenz. Between Konstanz and Kreuzlingen the river flows
into the "Untersee" and flows out of the Lake Constance near Stein am
Rhein as the "Seerhein". The old river course with all its turns and bends
is still easily recognized, even though the Alpine Rhine valley (lower
right) is very densely populated. The curving "old" Rhine forms a delta,
which advances into the lake at a rate of approximately 20 m annually.
A new flatfloored section of the Rhine, the "Alpine Rhine" was dug and
its banks reinforced in 1900 to prevent flooding. It flows into the lake
further to the east as a second tributary of Lake Constance. The peaks
of Mount Säntis (2502 m) rise majestically to the west of the Alpine
Rhine valley, to the east the Bregenz Forest is visible.

Lake Constance functions as a natural reservoir, allowing only moderate
amounts of water to pass into the "Seerhein" near Stein am Rhein, even
at high water. The lake also stores and reflects heat, contributing to
the fertility of its fruit-growing and wine production areas in neighboring
regions and, in particular, on its islands.

The pyramids of Xochicalco are located approximately 30 km southwest
of the city of Cuernavaca in Morelos state. Morelos, with an area of some
4,950 square km, is the second smallest of Mexico's 31 states and lies
between 1000 m and 3300 m elevation. Morelos is one of the most densely
populated areas of Mexico and directly borders the largest metropolis
in the world, Mexico City, to the north.

Cuernavaca itself, the state capital, has over a half a million inhabitants.
Thanks to its ideal climate, with mean annual temperatures of around 25oC,
and its superhighway connections with Mexico City, Cuernavaca is a favorite
relaxation spot for harried big city dwellers. Archeologists estimate
that Morelos has been inhabited for the last 3500 years as a consequence
of its ideal climatic conditions. The Spanish conquistador Hernán
Cortéz conquered Cuernavaca and its surrounding territories in
1521, before continuing on to conquer the Aztec capital of Tenochtitlán,
later the site of Mexico City.

Xochicalco, the "City of Flowers", was built upon a hill, the crest
of which was razed so that the temple could be built there. This well-planned
complex, with the Pyramid of the "Feathered Serpent", the observatory
and three ball courts, can be seen in this aerial photograph. Although
the first monumental structures can be traced back to the pre-Classic
periods, lasting from 900 to 800 B.C., Xochicalco achieved its greatest
cultural importance between 700 and 900 A.D. Strategically located as
it is between the central highlands and the Pacific coast, Xochicalco
became one of the most important urban centers in Mesoamerica, particularly
after the conquest of Teotihuacán and its temples, the largest
in Mexico.

Various highly sophisticated Mesoamerican cultures, such as the Olmecs,
Mixtecs, Zapotecs, Mayas and Aztecs, were blended in Xochicalco. And it
was in Xochicalco where the most highly developed system of hieroglyphic
writing in the entire Mexican highlands was discovered. At its height,
Xochicalco was an important center for military, trade, cultural and scientific
activities. In the observatory an 8-m-deep vertical tunnel leading to
a cave was dug. Twice each year, on May 15 and July 29, the sun shines
through the tunnel directly into the cave, which is part of an artificial
system of caves. Although the exact purpose of this tunnel is not clear,
it is assumed that Mesoamerican astronomers met regularly in Xochicalco
to improve the accuracy of the Mayan calendar and to pursue other studies.